Shiyun had 120 pencils.
45 of them were brown pencils and the rest were pink pencils. After she had given away some brown pencils, the ratio of the number of brown pencils to the number of pink pencils became 7 : 8. How many pencils did she have in the end?
| |
Brown |
Pink |
Total |
| Before |
4x8 =
32 u |
1x8 =
8 u |
5x8 =
40 u |
| Change |
- 25 u |
|
|
| After |
7 u |
8 u |
15 u |
The number of pink pencils remained unchanged.
LCM of 1 and 8 = 8
Total number of pencils at first = 40 u
40 u = 120
1 u = 120 ÷ 40 = 3
Number of pencils that Shiyun had in the end
= 7 u + 8 u
= 15 u
= 15 x 3
= 45
Answer(s):45
